Declension table of ?dṛvan

Masculine	Singular	Dual	Plural
Nominative	dṛvā	dṛvāṇau	dṛvāṇaḥ
Vocative	dṛvan	dṛvāṇau	dṛvāṇaḥ
Accusative	dṛvāṇam	dṛvāṇau	dṛvṇaḥ
Instrumental	dṛvṇā	dṛvabhyām	dṛvabhiḥ
Dative	dṛvṇe	dṛvabhyām	dṛvabhyaḥ
Ablative	dṛvṇaḥ	dṛvabhyām	dṛvabhyaḥ
Genitive	dṛvṇaḥ	dṛvṇoḥ	dṛvṇām
Locative	dṛvṇi dṛvaṇi	dṛvṇoḥ	dṛvasu

Compound dṛva -

Adverb -dṛvam